FCC Expands Spectrum Available for Outdoor Wi-Fi in 5-GHz Band

April 10, 2014

The FCC has instituted new rules that will make 100 MHz of spectrum in the 5-GHz band more accessible for use in public spaces, such as convention centers, parks and airports. Existing 5-GHz Wi-Fi rules and equipment authorization procedures for devices were streamlined, as well.

With the rule changes, the commission hopes to promote Wi-Fi speeds of one gigabit per second or more, as well as increasing overall capacity, reducing congestion at Wi-Fi hotspots and increasing the unlicensed spectrum innovation.

The Wi-Fi Alliance applauded the FCC’s move, saying in a prepared statement: “As a result of these new rules, operators and enterprises will soon be able to improve their Wi-Fi services. The ruling is particularly useful for the latest, gigabit-speed generation of Wi-Fi, Wi-Fi Certified [802.11ac].”

In 1997, the FCC allocated 300 megahertz of spectrum for use by U-NII devices. The commission established rules for the 5.15-5.25 GHz (U-NII-1 band), which operated at 50 milliwatts, indoor only; 5.25-5.35 GHz (U-NII-2A band), which operated at 250 milliwatts; and 5.725 5.825 GHz (U-NII-3 band), which operated at 1 watt. In 2003, an additional 255 megahertz of spectrum were allocated for U-NII devices at 5.47-5.725 GHz (U-NII-2C band), which operates at 250 milliwatts.

The new rules affect unlicensed National Information Infrastructure (U-NII) devices, which operate in 555 megahertz of spectrum in the 5 GHz band, and are used for Wi-Fi and other high-speed, wireless connections. The current restriction on indoor-only use was removed and the permissible power was increased in the 5.150-5.250 GHz band, which provides for more robust access to hotspots. This, in turn, will allow U-NII devices to better integrate with other unlicensed portions of the 5-GHz band.

Per the Report and Order, the FCC permits any device under the control of an access point to operate U-NII-1 band at power levels up to 250 milliwatts with a 6 dBi gain antenna. Power must be reduced for every decibel that antenna exceeds 6 dBi. The FCC believes these rules will protect incumbent GlobalStar’s license mobile satellite service.

“The action we take today will permit outdoor use in the U-NII-1 band and harmonize power levels with those in the U-NII-3 band,” Commissioner Michael O’Rielly said in a statement. “This harmonization will allow consumers to benefit from the new Wi-Fi standard that will increase data speeds.

“Along with the enhanced use of the U-NII-1 band, the item provides safeguards that will facilitate corrective action should large deployments result in harmful interference to licensed services.”

The FCC extended the upper edge of the 5.725-5.825 GHz band to 5.85 GHz and consolidated the Part 15 rules to apply to all digitally modulated devices operating in the spectrum to protect authorized users from harmful interference.

The Commission improved protection for incumbent systems by requiring manufacturers to secure their devices against illegal modification, which could cause interference to incumbent users in the band. Technical rules were also modified to protect Terminal Doppler Weather Radar (TDWR) systems and other radar systems operating in the 5.250-5.350 GHz and 5.470-5.725 GHz bands from interference.